Socket for radio instruments



Dec. 25,1928. 1,696,649 RLW. SEABURY a sbcxm' FOR RA'DIQ INSTRUMENTS Filed Jan. 20, 1.923

fig-mg Dee 192a.

" UNITED STATES PATENI; caries.

3101mm) w. snammr, or noonr'on, NEW JERSEY, assrcnoa'ro m rn'nounxcx momroams, mconroaa'rnn, or noon'ron, NEW masnrfa conrom'rrou or NEW mnsnr,

SOCKET FOR RADIO INSTRUMENT-S;

This invention relates to sockets for vacuum tubes ofthe audion type and transformers or other radio instruments such as are used in connection with the wireless trans-J.

been made heretofore of metal, which is,

however, objectionable for several reasons, particularly as introducing an undesired capacity into the circuit and as increasing the liability to current leakage. Such sockets have also been molded from insulating materials but have proven fragile and unreliable, being particularly liable to fracture at the bayonet lock.

In all high frequency circuits, and partico ularly those traversed by radio frequency currents the ca acity between adjacent parts of the circuit s ould be reduced to*a*"minimum.

The common practice in amplifying radio :frequency currents is. to employ a plurality of audions and transformers which are coupled to each other by suitable leads. To reduce the capacity between the several leads, the instruments are'placed close to each'other and short leadsare employed. Even with this arrangement, however, the capacity effect between adjacent parts of .the'circuit exerts an undesirable influence upon the circuits.

An object of the present invention is to provide a simple, strong, and eflicient socket which may be molded integrally from suitable insulating materials, particularly those of the so-called phenolic condensation product type. A further object of the invention 5 is to provide a multiplex socket for receiving audion tubes and transformers in which the capacity effectbetween the circuit connections is reduced to a minimum.

Preferred forms of sockets embodying my invention are illustrated in the accompanying drawings wherein Figs. 1, 2, and 3 are respectively, a plan, a vertical section on line 22 of Fig. 1, and. a bottom view of a single unit socket,

Fig. 4 is a plan viewofjtwo duplex sockets, illustrating theusual arrangement of a air of'such sockets and diagrammatically i usj trating the instruments placed in and the circults established'in one socket, ,QF1g.'5"-1sran elevation partly in Vertical section amines-5 of; ig. 6, and

The single unit form chosen for illustration in Figs. 1, 2, and 3 com rises an imperfora'te'tubular' wall or barre portion 10 and a surrounding flan e 11, the latter having a downwardly turne rim 12. The flange is perforated as indicated at 13 to receive the attachment screws, and at 14 to receive screws for securing the usual radial metal strips (not shown) serving as contacts for the prongs or terminals of the lamp. Ribs 15 on the lower face of the flange 11 act as guides for these contact strips.

As indicated, the barrel is preferably formed with a smooth, imperforate and slightly tapered outer face, but interiorly is provided with a plurality of p-roj ecting bearmg surfaces 16 accurately dimensioned to engage and support the cylindrical base of the vacuum tube. These bearing faces are of reduced area relative to the base of the vacuum tube, extending only through a portion of the height of the barrello d b ing arated moreover by recesses 17 One efl'ect of this arrangement is to provide an air space partially enveloping the-base of the socket, and a substantial clearance between the walls of the tube base and the socket. This has been found to improve materially the operation of the tube.

The bayonet lock is provided by an opening 18 in the flange 17 which projects inwardly from the top of the barrel wall 10 and overlies the several. recesses 17 and by a lateral extension 18' of the bearing surface 16 which is adjacent the opening 18. The cylindrical faces of the flange 17 and the. exten sion 18' are preferably formed as extensions of the surfaces 16.

By bayonet lock I do not limit myself to this particular arrangement of opening and lateral extension, but contemplate broadly any means carried by the socket adapted to engage a stud upon the instrument base by a rotary. motion thereof. I It will be observed that the bayonet lock lies wholly .within the outer circumference of the barrel 10, so

, that the integral outer wall is available as a reinforcement for the lock.

This strongly reinforces the construction at a region which is that of minimum strength-inthose constructions in which the bayonet lock takes the form of a slot extending through the barrel.

Briefly, the principal advantages of the described construction are:

The reduced area of bearing surface for the tube socket, coupled with the reinforcement by the external barrel, integral with these surfaces.

The'provision of a bayonet lock upon or contiguous to the inner face of the barrel.

The form illustrated in Figs. k6, comprises an audion receiving barrel portion and a second barrel portion 21 for receiving a transformer having a base and terminals which conform in size and arrangement to the standard audion base and terminal construction. Both of the barrels are carried by a surrounding base or panel 22 which is provided wit-h a downwardly turned rim 23, and both barrels preferably include bearing ribs 24 and a reinforced bayonet lock 25 such as included in the single unit construction. The flange or panel 22 is perforated near each corner and at a point along one side and near the barrel 20 to provide openings 26 for receiving binding post-s 27 which secure contact strips 28 to the socket and serve as terminals for connection to the appropriate external circuit-s. The flange or panel 22 is also provided with metal inserts 29, 30, and 31 which receive screws 32 that serve to attach contact strips 28 which form parts of the internal connections of the duplex socket, i. e., they engage the plate terminal of the audion, the input terminal of the primary winding of the transformer and the low side of the secondary winding. The circuit between the plate of the audion and the input side of the transformer is completed by a strap or wire 33 which is held in place by the attaching screws which enter the inserts 29 and 30. Similarly, the circuit between the low side of the transformer secondary and the A battery negative is completed by a strap or wire. 3 which is held in contact with the appropriate contact strips by the F bindingpost and the screw 32 which enters the insert 31. The lower faceof the flange 22 carries ribs 35 which provide recesses within which the several contact strips 28 and the connecting straps or wires 33 and 34 are located and sup-ported against lateral movement.

Individual reference characters have not been placed on the several contact strips and terminals. as it is believed that the various circuits which are established to and in the socket willbe apparent from the diagrammatic representation of the circuits which appears in Fig. 4. The characters which are ieee'eae molded in the flange 22 adjacent the terminals indicate that the terminals are to be connected to the filament current source, (F- and F-t); the input lead, (G the output lead (G and the B battery B).

It will be noted that the multiplex socket provides. a very compact mounting for an audion and a transformer and that the connections between the two devices are not only reduced to a minimum, but are so located between ribs of high insulating properties that the capacity eflect is reduced to a point far below that which has been obtained in prior constructions which employ separate mountings for these devices. The socket may be readily incorporated in a circuit with a minimum amount of wiring, and when several" stages of amplification are employed the circuit for the incoming wave is completed between adjacent sockets by a lead 36 which.

connects the G terminal of one socket to the G terminal of the next socket.

It will be understood that the invention is not limited to the particular forms illustrated by way of example. For example, the barrel may be rectangular or polygonal in contour and the flange may be modified and extended as may be desired to provide means of support or attachment for the usual appurtenances of the yacuum tube, such for example ,as the filament rheostat. The flange of the multiplex socket may be extended to provide a support for a plurality of sets of barrels which receive audions and transformers, and the internal connections of the socket may be formed in various ways,

as by straps which are embedded in the material of the socket during the molding process or the connecting strap and contact strips may comprise a single metal stamping. These and many other changes which may be made in the various elements, their size, shape and relative position, fall within the scope of my invention.

I claim:

1. An instrument socket comprising a tu-' bular wall portion of insulating material integrally provided with an interiorly extending flange and a plurality of spaced interior bearing surfaces depending therefrom and adapted to make discontinuouscontact with an instrument base.

2. An instrument socket comprising an exterior wall portion of insulating material integrally provided with an interiorly extending flange, integral interior spaced bearing surfaces dependingfrom said flange and adapted to make discontinuous contact with an instrument base, and an integral bayonet lock formed in one of said depending surfaces and adapted to receive a projecting stud upon said instrument base.

3. A radio instrument socket comprising a tubular wall portion of insulating mate-- rial, aninwardly projecting flange, a pluralular wall for engaging an instrument base, and a bayonet lock comprising a lateral extension of one of said bearing surfaces.

4. A radio instrument's ocket comprising a tubular wall portion of'insulating material, a plurality of s aced bearin surfaces projecting inwardly rom said tu ular wall for engaging an instrument base, a flange at the top of said wall portion and overlying said bearing surfaces, and a bayonet lock comprising an opening through said flange .and a lateral'extension of one of said bearing surfaces.

5. A multiplex instrument socket comprising a common" base of insulating material Y and a plurality of integral instrument-re;

ceiving portions. each comprising an exterior wall portion of insulating material,- an in-'- wardly projecting flange and integral in-" terior bearing surfaces, depending-therefrom with aninstrument base.

In testimony whereof, I aflix my'signat'ure.

RICHARD W. SEABURY,

and 'adated to make discontinuous contact 

